Convert Custom PHP Web Application to YII

I am looking to convert a custom PHP Web Application to the YII Framework.

I am in need of a skilled developer with YII experience. I have been tasked with converting an existing PHP web application to the YII framework. Without getting too much into the details, this web application was originally designed to track prospect from a lead generation website. It was then expanded to encompass other business functions besides sales and marketing.

In the initial implementation, we did our best to design for the system as we envisioned the end-sate, but many parts of the application were pieced together as they came. Currently, the presentation, business and data layers are not separated in many portions of the application. The goal of this re-design is to further improve upon functionality and usability, but with an emphasis on re-usability and maintainability. Now that we have a good understanding of the requirements as a whole, we can use this opportunity to turn out a much improved version of the software.

Here are some of the main areas where I would like to improve the application:
-Browser compatibility issues, currently there are some portions of the application that do not work in all major browsers.
-Clearly separate the presentation, data and business logic
-Re-use common features (Notes and detail screen is a good example)
-Make the application more user-friendly (Calendar Feature / “Save All” instead of multiple save buttons / etc)
-Implement data validations